Immunoelectron microscopy of cationized bovine serum albumin-induced glomerulonephritis in the rabbit.

Chronic immune complex glomerulonephritis was induced in a group of New Zealand white rabbits by daily intravenous injections of cationized bovine serum albumin (cBSA). The animals were serially killed and renal tissue was embedded in the hydrophilic resin Lowicryl K4M for immunoelectron microscopy. The results demonstrate the progressive deposition of rabbit IgG in the glomerular basement membrane in this model, with aggregation of immunoglobulins occurring only in the subepithelial space. Proteinuria developed concurrently with this event. Glomerular visceral epithelial cell (GVEC) endocytosis of immune material was observed at various stages of the disease process, suggesting that GVECs may be part of a clearance mechanism acting within the glomerulus.